docs: add additional badges

README.md

@@ -1,6 +1,10 @@
-[![NPM version](http://img.shields.io/npm/v/gitdown.svg?style=flat-square)](https://www.npmjs.org/package/gitdown)
+# Gitdown
+
 [![Travis build status](http://img.shields.io/travis/gajus/gitdown/master.svg?style=flat-square)](https://travis-ci.org/gajus/gitdown)
-[![Dependency Status](https://img.shields.io/david/gajus/gitdown.svg?style=flat-square)](https://david-dm.org/gajus/gitdown)
+[![Coveralls](https://img.shields.io/coveralls/gajus/gitdown.svg?style=flat-square)](https://coveralls.io/github/gajus/gitdown)
+[![NPM version](http://img.shields.io/npm/v/gitdown.svg?style=flat-square)](https://www.npmjs.org/package/gitdown)
+[![Canonical Code Style](https://img.shields.io/badge/code%20style-canonical-blue.svg?style=flat-square)](https://github.com/gajus/canonical)
+[![Twitter Follow](https://img.shields.io/twitter/follow/kuizinas.svg?style=social&label=Follow)](https://twitter.com/kuizinas)
 
 Gitdown adds [additional functionality](#features) (generating table of contents, including documents, using variables, etc.) to [GitHub Flavored Markdown](https://help.github.com/articles/github-flavored-markdown/).